Fluorinated melt ester additives for thermoplastic fibers

ABSTRACT

A composition having repellency to low surface tension fluids comprising a material prepared by forming a mixture of a polymer selected from the group consisting of polyolefin, polyamide, polyester, polyacrylate, and blends and copolymers thereof, and a fluorochemical compound comprising a fluorocarbon/hydrocarbon ester of the formulae: 
     
         R.sub.f --O--C(O)--R.sub.1 or R.sub.f --C(O)--O--R.sub.1 
    
     wherein 
     R f  is selected from the group consisting of: 
     1) F(CF 2 ) x  --(CH 2 ) m  wherein x is from about 4 to about 20 and m is from about 0 to about 6; and 
     2) F(CF 2 ) x  --SO 2  N(R 2 )--R 3  where x is a positive integer from about 4 to about 20, R 2  is an alkyl radical of from about 1 to about 4 carbon atoms, R 3  is an alkylene radical of from about 1 to about 12 carbon atoms; and 
     R 1  is an aliphatic hydrocarbon having from about 12 to about 76 carbon atoms; and 
     provided that said fluorochemical compound is other than perfluoroalkylethyl stearate; and 
     melt extruding the mixture.

This is a continuation of application Ser. No. 08/579,042 filed Dec. 21,1995, now abandoned.

FIELD OF THE INVENTION

This invention relates to a process for imparting superior repellency oflow surface tension fluids to thermoplastic polymers, in particularfibers, fabrics, nonwovens, films and molded articles by the addition ofcertain fluorinated esters to the polymer melt.

BACKGROUND OF THE INVENTION

Thermoplastic polymer fibers are frequently treated with fluorochemicalcompounds in order to affect the surface characteristics of the fiber,for example to improve water repellency or to impart stain or dry soilresistance. Most frequently, fluorochemical dispersions are appliedtopically to the fabrics made from these fibers by spraying, padding orfoaming, followed by a drying step to remove water.

For example, a method is known for obtaining dry soil resistance andnonflame propagating characteristics in a textile fiber by applyingtopically aqueous dispersions of a variety of fluorinated esters derivedfrom perfluoroalkyl aliphatic alcohols of the formula C_(n) F_(2n+1)(CH₂)_(m) OH where n is from about 3 to 14 and m is 1 to 3, togetherwith mono- or polycarboxylic acids which contain from 3 to 30 carbonsand can contain other substituents. The fluorinated esters include,among others, a perfluoroalkylethyl stearate corresponding to "ZONYL"FTS, as well as perfluoroalkylethyl diesters made from dodecanedioicacid or tridecanedioic acid.

It is well recognized that the process of manufacturing thermoplasticpolymeric fibers and fabrics could be simplified and significant capitalinvestment could be eliminated if the topical application were replacedby incorporating a fluorochemical additive into the polymer melt priorto the extrusion of the fiber. The difficulty has been in findingsuitably effective fluorochemical additives.

Thermoplastic polymers include, among others, polyolefins, polyesters,polyamides and polyacrylates. Polyolefins, and in particularpolypropylene, are frequently used for disposable nonwoven protectivegarments, particularly in the medical/surgical field, in part because ofa polyolefin's inherent water-repellency. However, polyolefins are notinherently good repellents for other lower surface tension fluidsfrequently encountered in the medical field such as blood and isopropylalcohol. To get around this deficiency, fluorochemical dispersions areapplied topically to these fabrics.

The requirements of an additive suitable for incorporating into apolyolefin melt include, besides the ability to repel low surfacetension fluids at a low concentration of the additive, a satisfactorythermal stability and low volatility to withstand processing conditions.Preferably the compound will migrate to the surface of the fiber so asto minimize the amount of additive needed for adequate repellency. Whilethis migration can often be enhanced by post-extrusion heating of thefiber, it is more preferable for the migration to occur without the needfor this heating step. This requirement for mobility in the polymericfiber in turn tends to limit the size of the fluorochemical molecule,and effectively eliminates from consideration high molecular weightpolymeric fluorochemical additives.

The general concept of incorporating fluorochemical additives into apolyolefin fiber melt is known, but the difficulty in finding suitableeffective additives has limited the application of this concept. Many ofthe past efforts to evaluate such fluorochemical additives have beenaimed at improving other properties of the polyolefin, and do not teachmethods of its improving repellency to low surface tension fluids.

Nonwoven composite structures are known consisting in part of two ormore melt-extruded nonwoven layers, at least one of which includes anadditive which imparts to the surface at least one characteristicdifferent than the surface characteristics of the polymer alone as aresult of preferential migration of the additive to the surface withoutthe need for post-formation treatment of any kind. Examples of theadditive-including layer include polypropylene modified by commerciallyavailable fluorochemical additives, including "ZONYL" FTS defined above.

U.S. Pat. Nos. 5,178,931 and 5,178,932 disclose specific nonwovenlaminiferous and composite structures respectively, consisting in partof three melt-extruded nonwoven layers, the second of which includes anadditive which imparts alcohol repellency as a result of preferentialmigration of the additive to the surface without the need forpost-formation treatment of any kind, and where at least one of thefirst and third layers has been treated by topical application of anagent to change its characteristics in some way. Examples of theadditive-including second layer include commercially availablefluorochemicals, including "ZONYL" FTS.

Soil resistant polymeric compositions are known which are prepared bymelt extrusion with a nonpolymeric fluorochemical dispersed throughoutthe polymer. The polymers used include polypropylene, polyethylene,polyamide and polyester, and the fluorochemical used is aperfluoroalkylstearate, in particular "ZONYL" FTS.

In addition, a polymeric composition is known comprising a mixture of apolymer selected from the group of polypropylene, polyethylene,polyamide and polyester with a fluorochemical comprising a fluorinatedoleophobic, hydrophobic alkyl group attached to a nonfluorinatedoleophilic alkyl, aryl, aralkyl or alkaryl moiety optionally through alinking moiety, which can be melt extruded as a mixture. A more specificdescription of the above fluorochemical is not disclosed, but among themany compounds which are applicable are esters where the oleophilicorganic group contains from 2 to 35 carbon atoms. Examples of such are"ZONYL" FTS or a product made by transesterifying "ZONYL" BA with methylstearate and methyl palmitate.

An automotive coating film is known containing an organicsolvent-soluble waxy hydrocarbon which possesses a fluorine-containingorganic group. This component is a product obtained by esterifying andcoupling a high molecular weight alcohol with a carboxylic acid whichpossesses a fluorine-containing group or a product obtained byesterifying and coupling a high molecular weight fatty acid and analcohol which possesses a fluorine-containing group. As examples of highmolecular weight alcohols included are those with average carbon chainlengths with up to 50 carbons. As examples of high molecular weightfatty acids included are those with carbon chain lengths of up to 31carbons (mellisic acid). The products were tested only as a waxing agentfor automobiles.

Japanese Patent Application 3-41160 to Kao Corp. teaches a thermoplasticresin composition containing a perfluoroalkyl group-containing longchain fatty ester of the formula R_(f) --R₁ --OCO--R₂ where R_(f) is aperfluoroalkyl group with 5 to 16 carbons, R₁ is an alkylene group with1 to 4 carbons, and R₂ is an unsaturated alkyl group or a saturatedalkyl group with 21 to 50 carbons. One example reacts C₈ F₁₇ C₂ H₄ OHwith C₂₇ H₅₅ COOH to produce the ester. The resins included polyethyleneand polypropylene. Benefits of the additive were shown by the contactangle of water with molded articles of the resin. No tests are reportedon the repellency to low surface tension fluids of the resultingpolymers.

In summary, while the prior art discloses numerous examples ofpolyolefin fibers containing a fluorochemical additive incorporated atthe melt stage to alter the surface characteristics of the extrudedfiber, much of this was aimed at soiling and staining resistance, waterrepellency or other purposes. Those references which were aimed atimparting alcohol repellency to polyolefin fabrics employ "ZONYL" FTS. Aneed exists to achieve superior repellency to low surface tension fluidsand superior product efficiency. The fluorinated compounds of thepresent invention meet this need.

SUMMARY OF THE INVENTION

The present invention comprises a composition and a process forimparting repellency of low surface tension fluids to thermoplasticpolymer articles. The composition having repellency to low surfacetension fluids of the present invention comprises a material preparedby:

forming a mixture of a polymer selected from the group consisting ofpolyolefin, polyamide, polyester, polyacrylate, and blends andcopolymers thereof, and a fluorochemical compound comprising afluorocarbon/hydrocarbon ester of the formulae:

    R.sub.f --O--C(O)--R.sub.1 or R.sub.f --C(O)--O--R.sub.1

wherein R_(f) is selected from the group consisting of 1) F(CF₂)_(x)--(CH₂)_(m) wherein x is from about 4 to about 20 and m is from about 0to about 6, and 2) F(CF₂)_(x) --SO₂ N(R₂)--R₃ wherein x is a positiveinteger from about 4 to about 20, R₂ is an alkyl radical of from 1 toabout 4 carbon atoms, and R₃ is an alkylene radical of from 1 to about12 carbon atoms and R₁ is an aliphatic hydrocarbon of from about 12 toabout 76 carbon atoms; provided that said fluorochemical compound isother than perfluoroalkylethyl stearate; and melt extruding the mixture.

The present invention further comprises the above composition in theform of a filament, fiber, nonwoven fabric or web, film or moldedarticle.

The present invention further comprises a process for impartingrepellency of low surface tension fluids to a thermoplastic polymerarticle comprising forming a mixture prior to article formation of apolymer and an effective amount of a fluorochemical compound comprisinga fluorocarbon/hydrocarbon ester as defined above and melt extruding themixture. Such articles include filaments, fibers, nonwoven webs orfabrics, films or molded articles.

DETAILED DESCRIPTION OF THE INVENTION

Superior repellency to low surface tension fluids is imparted tothermoplastic polymer articles, in particular fibers, fabrics,filaments, nonwovens, films, and molded articles, by the addition ofcertain monomeric fluorinated ester compounds to a polymer prior toarticle formation and melt extruding the resulting mixture. This processis used either with or without post-extrusion heating of the article topromote movement of the additive to the article surface, since the estercompounds of this invention tend by their nature to concentrate on thesurface.

The term "low surface tension fluids" is used herein to mean fluidshaving a surface tension of less than 50 dynes/cm (50×10⁻⁷ newtonmeter). Examples of such fluids include alcohols, blood, and certainbody fluids.

The composition of the present invention comprises a material preparedby melt extruding a mixture of a polymer selected from the groupconsisting of polyolefin, polyamide, polyester, polyacrylate, and blendsand copolymers thereof, and a fluorochemical compound, other thanperfluoroalkylethyl stearate, comprising a fluorocarbon/hydrocarbonester of the formulae:

    R.sub.f --O--C(O)--R.sub.1 or R.sub.f --C(O)--O--R.sub.1

wherein R_(f) in the above formulas is F(CF₂)_(x) --(CH₂)_(m) wherein xhas a preferred average value of about 7 to 10 and a range of about 4 toabout 20 and m has a value of 0 to 6.

Especially preferred for R_(f) is a composition wherein the chain lengthdistribution is as follows:

    ______________________________________    x = 6 or less        0-10%  by weight    x = 8               45-75% by weight    x = 10              20-40% by weight    x = 12               1-20% by weight    x = 14 or greater    0-5% by weight.    ______________________________________

This composition range, when m=2, and x has an average value of about 9,is hereinafter referred to as Telomer BN. This definition of R_(f) inthe formula R_(f) --OH is referred to as Telomer BN alcohol.

Alternatively R_(f) is a fluorinated sulfonamide of the structureF(CF₂)_(x) --SO₂ N(R₂)--R₃ wherein x is a positive integer from about 4to about 20, preferably 4 to 10 inclusive, R₂ is an alkyl radical havingfrom 1 to 4 carbon atoms, and R₃ is an alkylene radical having from 1 to12 carbon atoms. Preferably R₂ is CH₃ and R₃ is --CH₂ CH₂ --, --(CH₂)₃--, or --(CH₂)₄ --.

The fluoroalkyl portion of the alternative R_(f) structure is afluorinated, preferably saturated, monovalent, non-aromatic, aliphaticradical of at least three fully fluorinated connected carbon atoms in achain. The chain in the radical is straight, branched, or, ifsufficiently large, cyclic and is optionally interrupted by divalentoxygen atoms, hexavalent sulfur atoms, or trivalent nitrogen atomsbonded only to carbon atoms. A fully fluorinated aliphatic radical ispreferred, but hydrogen or chlorine atoms are optionally present assubstituents in the radical provided that not more than one atom ofeither is present in the radical for every two carbon atoms.

R₁ is an aliphatic hydrocarbon with a carbon chain length of about 12 toabout 76 carbons, preferably from about 24 to about 50 carbons. Alcoholscorresponding to R₁ --OH are commercially available from PetroliteCorporation, Polymer Division Headquarters, 6910 E. 14th Street, Tulsa,Okla., USA 74112, under the trademark "UNILIN". "UNILIN" alcohols arefully saturated long chain linear alcohols. The approximate R₁ ranges of"UNILIN" 350, 425, 550 and 700 are 12 to 50, 14 to 58, 16 to 56 and 14to 66, respectively. The average chain lengths for "UNILIN" 350, 425,550 and 700 are about 24, 32, 40 and 48, respectively. These arepreferred for use in the present invention. Acids corresponding to R₁--COOH are commercially available from Petrolite Corporation, PolymersDivision Headquarters, 6910 E. 14th Street, Tulsa, Okla., 74112, underthe trademark "UNICID". The range of average chain lengths for "UNICID"350, 425, 550 and 700 are 24-29, 29-37, 37-45 and 40-48, respectively.These are preferred for use in the present invention. More particularlythe "UNILIN" and "UNICID" carbon chain lengths are as noted in Table A.

                  TABLE A    ______________________________________                  GC DATA**    UNILIN   Lit. Avg.* % Alcohol                                 Range   Average    ______________________________________    350      C24-26              C12-46  C24-26    425      C30-32     85.0     C14-58  C30-32    550      C40-42     79.5     C16-56  C38    700      C48-50     83.6     C14-66  C50    ______________________________________                  GC DATA**    UNICID   Lit. Avg.* % Acid   Range   Average    ______________________________________    350      C24-29     79.0     C12-50  C28-30    425      C29-37    550      C37-45     80.0     C16-62  C42-44    700      C40-48              C16-76    ______________________________________     *Literature average     **Gas chromatography data

There are various methods by which the above compounds can be prepared,and the inventive process is not limited to a particular method ofpreparation. For example, the above compounds are conveniently made byreacting an appropriate fatty alcohol with the appropriate fluorocarbonacid to form an acid ester, or by reacting an appropriate fatty acidwith the appropriate fluorocarbon alcohol. Other compounds in thesegroups are readily made by those skilled in the art by following similarprocesses.

The esters useful in this invention are mixed with thermoplasticpolymers by adding them to pelletized, granular, powdered or otherappropriate forms of the polymers and rolling, agitating or compoundingthe mixture to achieve a uniform mixture which is then melt extruded.Alternatively the esters are added to a polymer melt to form a mixturewhich is then melt extruded. The thermoplastic polymer is a polyolefin,polyester, polyamide, or polyacrylate. The thermoplastic polymerpreferably is a polyolefin, mixture or blend of one or more polyolefins,a polyolefin copolymer, mixture of polyolefin copolymers, or a mixtureof at least one polyolefin and at least one polyolefin copolymer. Thethermoplastic polymer is more preferably a polyolefin polymer orcopolymer wherein the polymer unit or copolymer unit is ethylene,propylene or butylene or mixtures thereof. Thus the polyolefin ispreferably polypropylene, polyethylene, polybutylene or a blend orcopolymer thereof.

The amount of the fluorinated compound to be added to the thermoplasticpolymer is preferably between 0.1 and about 5% by weight of the polymer.Amounts above this range can be used but are unnecessarily expensive inrelation to the benefit received. The blend is then melted and extrudedinto fibers, filaments, nonwoven webs or fabrics, films, or moldedarticles using known methods. The fluorine content of the fiber,filament, nonwoven fabric or web prepared therefrom, film or moldedarticle is from about 200 ug/g to about 25,000 ug/g.

Extrusion is used to form various types of nonwovens. In particular,extrusion is used to form a melt blown nonwoven web of continuous andrandomly deposited microfibers having an average diameter ofapproximately 0.1 to 10 microns, preferably in the range of about 3 to 5microns. The melt extrusion is carried out through a die at a resin flowrate of at least 0.1 to 5 grams per minute per hole, with themicrofibers being randomly deposited on a moving support to form theweb.

In the above melt blowing process, polymer and a compound of the presentinvention are fed into an extruder where it is melted and passed througha die containing a row of tiny orifices. As the polymer emerges from thedie, it is contacted by two converging, high-velocity hot air streams,which attenuate the polymer into a blast of fine, discontinuous fibersof 0.1 to 10 microns in diameter. The useful polymer throughputs or flowrates range from 0.1 to 5 grams per minute per hole. Typical gas flowrates range from 2.5 to 100 pounds per square inch (1.72×10⁵ to 6.89×10⁵Pa) per minute of gas outlet area. The air temperature ranges from about400° F. (204° C.) to 750° F. (399° C.). Cooling air then quenches thefibers, and they are deposited as a random, entangled web on a movingscreen which is placed 6 to 12 inches (15.2 to 30.5 cm) in front of theblast of fibers.

Melt blowing processes are described in further detail in articles by V.A. Wente, "Superfine Thermoplastic Fibers", Industrial and EngineeringChemistry, Vol. 48(8), pp 1342-1346 (1956); and by R. R. Buntin and D.T. Lohkamp, "Melt Blowing--A One-step Web Process for New NonwovenProducts", Journal of the Technical Association of the Pulp and PaperIndustry, Vol. 56(4), pp 74-77 (1973); as well as in U.S. Pat. No.3,972,759 to R. R. Buntin. The disclosures of these documents are herebyincorporated by reference.

The unique properties of a melt blown nonwoven web comprised of a randomarray of fine, entangled fibers include very large surface areas, verysmall pore sizes, moderate strength and light weight fabric structure.These properties make the nonwoven webs particularly suitable for suchapplications as medical fabrics where barrier properties as well asbreathability and drape are important.

Extrusion is also used to form polymeric films. In film applications, afilm forming polymer is simultaneously melted and mixed as it isconveyed through the extruder by a rotating screw or screws and then isforced out through a slot or flat die, for example, where the film isquenched by a variety of techniques known to those skilled in the art.The films optionally are oriented prior to quenching by drawing orstretching the film at elevated temperatures.

Molded articles are produced by pressing or by injecting molten polymerfrom a melt extruder as described above into a mold where the polymersolidifies. Typical melt forming techniques include injection molding,blow molding, compression molding and extrusion, and are well known tothose skilled in the art. The molded article is then ejected from themold and optionally heat-treated to effect migration of the polymeradditives to the surface of the article.

An optional heating or annealing step can be conducted but is notrequired. The polymer melt or extruded fiber, filament, nonwoven web orfabric, film, or molded article is heated to a temperature of from about25° C. to about 150° C. The heating in some cases may improve theeffectiveness of the fluorochemical additive in imparting alcoholrepellency.

The compositions of the present invention are useful in various fibers,filaments, nonwoven webs or fabrics, films and molded articles. Examplesinclude fibers for use in fabrics and carpets, nonwoven fabrics used inprotective garments used in the medical/surgical field, and moldedplastic articles of many types. The process of the present invention isuseful for imparting repellency of low surface tension fluids to variousthermoplastic polymer articles such as filaments, fibers, nonwoven websor fabrics, films and molded articles.

EXAMPLE 1

Synthesis of R_(f) --O--C(O)--R₁, wherein R_(f) is an aliphaticfluorocarbon radical of formula F(CF₂)_(x) (CH₂)_(m) where the averagevalue of x is 9, m=2, and wherein R₁ has an average value of 32 carbonatoms.

A 250-mL flask was fitted with a mechanical stirrer, temperature controldevice, Dean-Stark trap, water condenser, nitrogen gas inlet tube andheating mantle. Into the flask were charged 79.1 g (0.15 mole)F(CF₂)_(n) CH₂ CH₂ OH where n=6-18, avg. n=9 and 89.4 g (0.15 mole)"UNICID" 425 Acid (C₂₉ -C₃₇ aliphatic acid from Petrolite Corporation,6910 E. 14th Street, Tulsa, Okla., USA, 74112, acid no.=94 mgKOH/g). Themixture was heated and held at 120° C. When the mixture was homogeneous,0.3 g phosphorous acid and 0.12 g boric acid were added. The temperaturewas raised to 140-145° C. and held for approximately 87 hours withcontinuous removal of water. When a gas chromatographic analysis of thereaction mixture indicated that all telomer BN alcohol had reacted, themixture was cooled slightly and discharged yielding 44.65 g (87%) ofproduct. Infrared analysis confirmed the above structure. The productwas a tan solid and melted at 66.65° C. by Differential ScanningCalorimetry (DSC). The percent fluorine found by analysis was 32.4%compared to a theoretical analysis of 33.4%.

EXAMPLES 2-15

These examples were prepared using the procedure of Example 1. Table 2lists the acid from which the fluoroester was prepared and thefluorocarbon distribution of the alcohol. All examples were used toprepare melt blown nonwoven webs and tested for alcohol repellency asdescribed in Example 16:

EXAMPLE 16 Step 1 Preparation of the Polymer Blend

Uniform mixtures of the fluorochemical additives produced in Examples1-16 together with a polyolefin were prepared by combining them androlling the mixture for about 24 hours. Comparative examples A-D usedthe monoester "ZONYL" FTS and were prepared in a similar manner. Inparticular, for the compound of Example 4, a uniform mixture of 16.1 g(1.2 weight %) of finely ground compound of Example 4, and 1,349 gEscorene PD3746G (Exxon Chemical Americas, P.O. Box 3273, Houston, Tex.77001) polypropylene resin having a melt flow rate of approximately 1000was prepared by rolling the mixture for 24 hours. The fluorineconcentration in the mixture was calculated to be 3300 μg/g fluorine.Actual fluorine concentration in the nonwoven web was 2930 μg/gfluorine. Comparative examples, designated A-D were prepared in the samemanner.

Step 2 Melt Blown Web Formation

Melt blown nonwoven webs were prepared from the above mixtures using a6-inch (15 cm) melt blowing pilot unit at a polymer feed rate of about0.4 gram/minute/hole. The polymer blends were fed into the extruderhaving three barrel zones at temperatures ranging from 175° C. to 250°C. The temperature at the die was from 200° C. to 260° C. and the airtemperature at the die varied from 200° C. to 270° C. The die tip gapwas 0.060 inches (0.15 cm) and the primary air pressure was 2.6 psi(17.9×10³ Pa). The webs were formed on a drum coated with "TEFLON" at anoutput of 0.4 gram/hole/minute and collected on a take-up roll operatingat 30 feet/minute(914 cm/minute) which resulted in the fabrics having abasis weight of 1.0 oz./square yard (34 gm/square meter).

Step 3 Repellency Testing

The water repellent properties of the melt blown webs were measuredusing an isopropyl alcohol/water test and are expressed in terms ofpercent isopropyl alcohol rating. Webs that resisted penetration of a100% isopropyl alcohol/0% water solution (lowest surface tension fluid)after 1-2 minutes were given the highest rating of 100. Webs that areonly resistant to a 100% water/0% isopropyl alcohol solution after 1-2minutes are given the lowest rating of 0. Table 1 lists ratings thatcorrespond to other isopropyl alcohol/water mixtures used in this test.The rating for a given fabric corresponds to the lowest surface tensionfluid (greatest % isopropyl alcohol/water solution) that does not wetthe fabric after 1-2 minutes.

                  TABLE 1    ______________________________________    Percent Isopropyl Alcohol Ratings                % Isopropyl alcohol/    Rating      % water (vol/vol)    ______________________________________    100         100/0    90          90/10    80          80/20    70          70/30    60          60/40    50          50/50    40          40/60    30          30/70    20          20/80    ______________________________________

To evaluate in-process repellency, the webs were rated immediately afterexiting the melt blown line and then after two days and after about oneweek. Table 2 summarizes the percent isopropyl alcohol data for thepolypropylene melt blown webs containing the esters of Examples 1-15 andthe comparison examples A-D containing "ZONYL" FTS available from E. I.du Pont de Nemours and Company, Wilmington, Del., at different fluorineconcentration levels. Also included in the table is a polypropylenecontrol sample (PP Control).

The results in Table 2 showed the clear advantage of the inventivecomposition over the comparative and control samples, the advantagesshowing up immediately and over time. A related advantage for theinventive composition is better performance at lower levels offluorochemical additive.

                                      TABLE 2    __________________________________________________________________________    Isopropyl Alcohol Repellency of Polypropylene Melt Blown Webs                   μg/g Fluorine                          Isopropyl alcohol repellency    Example         Dist.sup.1            Acid   Target/Actual                          As made                               2 days                                    1 week                                        Heated.sup.2    __________________________________________________________________________    1    BN "UNICID" 350                   1500/1480                          40   --   90-100                                        30.sup.a    2    BL "UNICID" 350                   1700/1480                          40   --   80  30.sup.a    3    BN "UNICID" 425                   3300/2930                          90    90-100                                    90-100                                        90.sup.b    4    BN "UNICID" 425                   3300/3120                          40   80   90  90.sup.b    5    BN "UNICID" 550                   3300/2720                          100  100  100 100.sup.b    6    BN "UNICID" 550                   3300/2790                          40   60   90  90.sup.b    7    BN "UNICID" 550                   1980/1910                          70-80         100.sup.a    8    BL "UNICID" 550                   1980/1570                          60   --   --  92.sup.a    9    BN "UNICID" 700                   3300/3210                          100  100  100 100.sup.c    10   BN "UNICID" 700                   4500/2760                          40        40  100.sup.b    11   BN "UNICID" 700                   1980/1780                          50-60                               80   90  70.sup.c    12   BN Stearic                   3300/2940                          70   80-90                                    90-100                                        80.sup.b    13   BN Stearic                   3300/3510                          30   60   80  70.sup.b    14   M  "UNICID" 550                   1980/1550                          40   50   80  50.sup.a    15   M  Stearic                   1980/1610                          30   40       30.sup.a    A    B  Stearic                   3300/3050                          70   80-90                                    90  80.sup.b    B    B  Stearic                   3300/3010                          30   60   80  60-70.sup.b    C    B  Stearic                   2875/2426                          40   80   80  80.sup.b    D    B  Stearic                   2423/1910                          30   70   70-80                                        80-90.sup.b    Control               20   20   20    __________________________________________________________________________     .sup.1 Fluorocarbon atom distribution: BL = C.sub.4 F.sub.9 --C.sub.8     F.sub.17 ; B = C.sub.4 F.sub.9 --C.sub.18 F.sub.37 ; BN = C.sub.8 F.sub.1     --C.sub.12 F.sub.25 ; M = C.sub.8 F.sub.17 SO.sub.2 N(CH.sub.2     H.sub.5)--(CH.sub.2).sub.2 --OH     .sup.2 Annealing process:     .sup.a Web was annealed at 176 F. (80° C.) for 15 seconds shortly     after processing     .sup.b Web was annealed at 140 F. (60° C.) for 25 hours about one     week after processing     .sup.c Web was annealed at 180 F. (82.20° C.) for 1 minute shortly     after processing

What is claimed is:
 1. A composition comprising a material preparedby:forming a mixture of a polymer selected from the group consisting ofpolyolefin, polyamide, polyester, polyacrylate, and blends andcopolymers thereof, and a fluorochemical ester composition of theformulae:

    R.sub.f --O--C(O)--R.sub.1 or R.sub.f --C(O)--O--R.sub.1

wherein R_(f) is selected from the group consisting of: 1) F(CF₂)_(x)--(CH₂)_(m) wherein x is from about 4 to about 20 and m is from about 0to about 6; and 2) F(CF₂)_(x) --SO₂ N(R₂)--R₃ wherein x is a positiveinteger from about 4 to about 20, R₂ is an alkyl radical of from 1 toabout 4 carbon atoms, and R₃ is an alkylene radical of from 1 to about12 carbon atoms; and R₁ is an aliphatic linear hydrocarbon having anaverage of from 30 to about 50 carbon atoms; and melt extruding themixture,wherein said composition is repellent to fluids having a surfacetension of less than 50 dynes/cm.
 2. The composition of claim 1 whereinthe polymer is selected from the group consisting of polyolefin, mixtureof polyolefins, olefin copolymer, mixture of olefin copolymers, andmixture of at least one polyolefin and at least one olefin copolymer. 3.The composition of claim 2 wherein the polymer has a polymer unit whichis ethylene, propylene, butylene, or a mixture thereof.
 4. Thecomposition of claim 1 wherein R_(f) is F(CF₂)_(x) (CH₂)_(m) wherein xis an average of about 9, and m is
 2. 5. The composition of claim 1wherein the fluorochemical is present in an amount of from about 0.1% toabout 5% by weight of the polymer.
 6. The composition of claim 1 havinga fluorine content of from about 200 ug/g to about 25,000 ug/g.